Watercraft



March 4, 1969 H. w. TULLENERS 3,430,595

WATERCRAFT Filed Feb. 20, 1967 Sheet of 4 ,zo Q

36 FIG-4 INVENTOR HARRY WERNER TULLENERS WM WW ATTORNEY March 4, 1969 H. w. TULLENERS 3,430,595

WATERCRAFT Filed Feb. 20, 1967 Sheet 2 of 4 March 1969 H. w. TULLENERS 3,430,595

WATERCRAFT Filed Feb. 20, 1967 v Sheet 3 or 4 32 {/MIMA FIG-M March 4, 1969 H. w. TULLENERS WATERCRAFT Sheet 4 014 Filed Feb. 20, 1967 FIG-2B United States Patent 24 Claims ABSTRACT OF THE DISCLOSURE A watercraft adapted to travel upon a smooth surface or upon a wavy surface while maintaining a load carrier portion of the watercraft relatively level. A lower pontoon and an upper pontoon are attached to the load carrier portion of the watercraft at each of opposite portions thereof. The lower pontoons are adapted to normally travel upon the surface of the water and to normally support the watercraft. The upper pontoons do not normally engage the water. The upper pontoons engage the water and assist in support of the watercraft only during travel of the watercraft upon a wavy surface.

Background of the invention In the past watercraft have been devised for rapid travel. However, rapid travel of the watercraft, particularly upon a wavy water surface, has resulted in rough travel of the watercraft.

Watercraft such as catamarans or hydrofoil Water vehicles have been devised. However, these watercraft, as well as other known watercraft, are designed to move upon the surface of the water and are not capable of wave piercing. Thus, known watercraft are not capable of rapid relatively smooth travel.

Thus, an object of this invention is to provide a watercraft which has portions thereof which are capable of movement through the water in submerged or partially submerged conditions. Thus, a watercraft of this invention is capable of smooth rapid travel upon a water surface which is smooth or wavy.

Other objects and advantages reside in the construction of the invention, combinations thereof, the method of manufacture, and the mode of operation, as will become more apparent from the following description.

Brief description of the drawings FIGURE 1 is a perspective view of a watercraft of this invention.

FIGURE 2 is a side elevational view of the watercraft of FIGURE 1.

FIGURE 3 is an enlarged front elevational view of the watercraft of FIGURES 1 and 2. The view of FIGURE 3 is taken substantially on line 3-3 of FIGURE 2.

FIGURE 4 is an enlarged sectional view taken substantially on line 4-4 of FIGURE 3.

FIGURE 5 is an enlarged sectional view taken substantially on line 55 of FIGURE 2.

FIGURE 6 is an enlarged sectional view, with parts broken away, taken substantially on line 66 of FIG- URE 2.

FIGURE 7 is an enlarged fragmentary elevational view taken substantially on line 77 of FIGURE 1.

FIGURE 8 is an enlarged fragmentary view of a portion of the ends of an upper and a lower pontoon of the Watercraft. FIGURE 8 ShOWs operation of the pontoons on a relatively smooth water surface.

FIGURE 9 is a fragmentary side elevational view, similar to FIGURE 8, and illustrating operation of the pontoons of FIGURE 8 in a wavy water surface.

FIGURES l0 and 11 are side elevational views on a smaller scale than FIGURE 2 and illustrating the movement of the watercraft upon a wavy surface.

FIGURE 12 is a fragmentary side elevational view, drawn on substantially the same scale as FIGURES 8 and 9, illustrating the operation of a pontoon upon a relatively smooth water surface, the pontoon having a forward end tip which is at substantially the longitudinal center of the pontoon. The pontoon of FIGURE 12 is not necessarily made according to this invention.

FIGURE 13 is a fragmentary side elevational view of a pontoon of this invention and illustrates the operation thereof upon a relatively smooth water surface, the pontoon having a forward end tip which is below the longitudinal center thereof.

FIGURE 14 is a fragmentary side elevational view showing the pontoon 0f FIGURE 12 and illustrating the operation thereof upon a wavy water surface.

FIGURE 15 is a fragmentary side elevational view showing the pontoon of FIGURE 13 and illustrating the operation thereof upon a wavy water surface.

FIGURE 16 is a fragmentary side elevational view showing a modification in the forward end portion of a pontoon of this invention.

FIGURE 17 is a perspective view drawn on substantially the same scale as FIGURE 1 and showing another watercraft of this invention.

FIGURE 18 is a front elevational view of the watercraft of FIGURE 17.

FIGURE 19 is a fragmentary side elevational view showing the forward portion of an upper pontoon and a lower pontoon of the watercraft of FIGURE 17 and illustrating the operation thereof upon a smooth water surface.

FIGURES 20 and 21 are fragmentary side elevational views showing the pontoons of FIGURE 19 and illustrating operation thereof upon a wavy water surface.

FIGURE 22 is an enlarged sectional view taken substantially on line 2222 of FIGURE 21.

FIGURE 23 is an enlarged fragmentary longitudinal sectional view of the forward portion of the lower pontoon shown in FIGURES 19, 20, and 21.

Summary 0] the invention The watercraft of this invention comprises a load carrier member which is adapted to be positioned a suflicient distance above the water surface that the load carrier member does not engage the surface of the water. The watercraft is provided with a main pontoon or fioat member on either side of the load carrier member and below the load carrier member. The two main pontoon members are elongate float members in which the transverse dimension thereof is very small in consideration of the length dimension thereof. The two main pontoons or floats are capable of supporting the load carrier member and the load thereof while each of the two main pontoons has a substantial portion thereof in a submerged condition. Above each main pontoon is an auxiliary pontoon, which has substantially the same length and transverse dimensions as the main pontoons. The auxiliary ontoons are adapted to assist in supporting the watercraft upon a water surface which is rough and wavy. Means are provided for connecting each main pontoon to its respective auxiliary pontoon and to the load carrier member.

Each pontoon is a wave piercing pontoon which is capable of readily moving through the water and through a wave so that the watercraft during travel over the surface of the water does not necessarily move up and down with the wave formation. Furthermore, due to the fact that the pontoons are adapted to move through waves rather than to move over the waves, the line of movement of the watercraft is as strai ht as possible and can therefore be faster, as well as smoother than is possible with other watercraft. Also, a minimum amount of energy i expended in propulsion of a watercraft of this invention.

Description of the preferred embodiments Referring to the drawings in detail, a watercraft 30 of this invention is shown in FIGURES 1, 2, and 3. The watercraft 30 is provided with a load carrier member or cabin 32. The load carrier member 32 may be of any suitable size or shape and is herein shown as being enclosed.

A plurality of leg members 36 and 38 are used to attach the load carrier member 32 to auxiliary pontoons or floats 40, there being one auxiliary pontoon 40 at each of the two sides of the cabin 32 and at a lower level than the cabin 32, as best shown in FIGURE 3.

FIGURE shows the manner in which the leg members 36 and 38 are attached to the load carrier member 32. The load carrier member 32 has a base 42. A flange 43 is integral with the base 42 and extends downwardly therefrom. A rigid connector member 44 joins each pair of leg members 36 and 38 together and to the flange 43 directly "below the base 42. Each of the leg members 36 and 38 and the connector member 44 may have a crosssectional appearance similar to that of the leg member 36 as shown in FIGURE 4, or each leg member 36 or 38 or the connector member 44 may have any other suitable appearance or shape.

The connector member 44 is pivotally attached to the flange 43 by means of a pin 46 which is adjacent the leg member 36. A support stem 50 is attached to the connector member 44 adjacent the leg member 38. The stem 50 extends loosely through an opening 52 in the base 42 and has a head 54 at the upper end thereof. A coil spring 56 encompasses the stem 50 between the base 42 and the head 54 and urges the stem 50 upwardly.

A coil spring 58 encompasses the stem 50 between the base 42 and the connector member 44 and urges the connector member 44 and the stem 50 downwardly. Thus, the coil springs 56 and 58 normally maintain the connector member 44 in the position shown in FIGURE 5 with respect to the base 42. However, the connector member 44 is pivotally movable with respect to the base 42, and thus the leg members 36 and 38 are movable with respect to the base 42.

The upper ends of each pair of leg members 36 and 38 are separated and spaced apart by the connector member 44. However, each pair of the leg members 36 and 38 converge downwardly and terminate within one of the upper or auxiliary pontoons 40 and are secured thereto, as shown in FIGURE 6.

A strut 60 has the upper end thereof pivotally attached to the leg member 36 within the auxiliary pontoon 40, there being at least one strut 60 for each pair of the leg members 36 and 38. A pin 62 pivotally attaches each strut 60 to its respective leg member 36. Each strut 60 may have a cross-sectional configuration similar to that shown in FIGURE 4 or may have any other suitable configuration. Each strut 60 extends through the lower portion of its respective auxiliary pontoon 40. An elastomeric bushing 63 joins each strut 60 to its respective auxiliary pontoon 40 and seals against passage of water into the auxiliary pontoon 40 between the strut 60 and the auxiliary pontoon 40, while permitting the strut 60 to move with respect to the auxiliary pontoon 40.

A compression spring 64 is disposed within each auxiliary pontoon 40 between each leg member 36 and its respective strut 60. A compression spring 66 is disposed within each auxiliary pontoon 40 between each leg member 38 and its respective strut 60. Thus, each pair of compression springs 64 and 66 urge each strut 60 to a position midway between the respective leg members 36 and 38, as shown in FIGURE 6. However, pivotal movement of the strut 60 is permitted, as illustrated in FIG- URE 6.

An elongate main pontoon or float 68 is attached to the lower end of the struts 60 which extend downwardly from each auxiliary pontoon or fioat 40. Thus, there is one main pontoon 68 disposed below each of the auxiliary pontoons 40 and joined thereto through struts 60.

Each main pontoon or float 68 and its respective auxiliary pontoon 40 are substantially equal in length dimension and in transverse dimension. Preferably each pontoon 40 and 68 is circular in cross-section. Also, preferably, each pontoon 40 and 68 has a length to diameter ratio in the range of from 10 to 1, to 50 to 1. If desired, however, each main pontoon 68 and each auxiliary pontoon 40 may comprise a plurality of axially aligned spaced-apart pontoons attached to struts 60 and to leg members 36 and 38.

The forward end of each of the main pontoons 68 has a tip 70 which is below the longitudinal axis of the pontoon 68. Preferably, the tip 70 of each main pontoon 68 is located at a position which is approximately onequarter of the height of the pontoon 68.

However, preferably, each auxiliary pontoon 40 has a tip 74 at the forward end thereof which is on the longitudinal axis thereof.

Each of the main pontoons 68 is provided with a plurality of trim tabs or fins 76 which are preferably pivotally adjustable for steering and/or for other control of the watercraft 30.

At the central portion of each of the main pontoons 68 is a housing 80 which contains any suitable engine means or motor means, not shown, which is operably connected to a propeller 82 for rotation thereof for propulsion of the watercraft.

FIGURES 4, 5, and 6 show a conduit 84 and a conduit 85 which extend from the load carrier member 32 through the leg members 36 and through the auxiliary pontoons 40 and through the struts 60 and through a portion of the main-pontoons 68 to the engine or motor means within the housings 80. The conduits 85 may serve to provide air to the motor means or engine means within the housing 80 and control conductors 87 or the like may extend through the conduit 84 to the engine or motor within the housing 80.

Operation The water-craft 30 is propelled by operation of the propeller members 82 or by operation of any other suitable propulsion means.

Each of the main pontoons 68 is created so that when a normal load is carried by the load carrier member 32, a substantial portion of each of the main pontoons 68 is submerged. Preferably, each main pontoon or float 68 is normally substantially one-half submerged when a load is carried by the load carrier member 32. Thus, regardless of the surface conditions of the water which supports the watercraft 30, each of the main pontoons 68 tends to maintain a ratio of one-half of the total exterior surface thereof submerged and one-half of the total exterior surface thereof unsubmerged. For example, FIGURE 2 illustrates movement of the watercraft 30 upon a wavy water surface 94. Along the length of each main pontoon 68 there are alternate portions thereof which are completely submerged and alternate portions thereof which are completely unsubmerged. Thus, substantially one-half of the total volume of each pontoon or float 68 is normally submerged and substantially one-half of the total volume thereof is normally unsubmerged.

Each of the main pontoons 68 is very long in consideration of its transverse dimension. Thus, each of the main pontoons 68 is capable of traveling through waves of water by wave piercing action, as illustrated in FIGURES 2 and 9. The forward end portion of each of the main pontoons or floats 68 is created to provide optimum wave piercing action. As shown in FIGURES 2, 8, 9, 13, and 15 and as discussed above, each main pontoon 68 has a forward tip 70 which is below the longitudinal axis of the pontoon 68. Preferably, each main pontoon 68 has a forward tip 70 which is located at a position which is approximately one-quarter of the height dimension of the pontoon 68.

Thus, as each main pontoon 68 travels forwardly as illustrated by an arrow 90 in FIGURES 13 and 15, the tip 70 thereof is normally below the surface of the water. In FIGURE 13 the water is shown as having a substantially smooth surface. However, due to the fact that the tip 70 is below the surface of the water, as the pontoon 68 moves forwardly, water is forced to flow over the forward end of the pontoon 68 as illustrated by a flow pattern 97 in FIGURE 13. Thus, water pressure is created upon the forward end portion of the pontoon 68, as illustrated by arrows 92 in FIGURE 13, urging the forward end of each pontoon 68 downwardly. The downward pressure as illustrated by the arrows 92 is balanced a predetermined amount by an upward pressure on the forward end of each pontoon 68, as illustrated by arrows 93 in FIGURE 13. The amount of balancing pressure illustrated by the arrows 93 is such that the pontoons 68 tend to move forwardly while remaining substantially horizontal.

FIGURE 12 shows a forward end portion of a pontoon 95 which is not necessarily made according to the preferred embodiment of this invention. The main pontoon 95 has a tip 96, as shown in FIGURE 12, which is located on the longitudinal axis of the pontoon 95. Therefore, if a smooth water surface 100 exists, the tip 96 would normally be located at the smooth water surface 100 shown in FIGURE 12. Thus, as the pontoon 95 is moved forwardly, as shown by an arrow 99, water at the lower forward surface of the pontoon 95 produces an upward pressure or force, as illustrated by arrows 102. Thus, there is a resulting lifting effect upon the forward end portion of the pontoon 95, and the forward end of the pontoon 95 would tend to rise. Thus, as the pontoon 95 is moved rapidly forwardly a planing action of the pontoon 95 would occur. The planing action would tend to cause the pontoon 95 to travel over the smooth water surface 100 rather than to travel in or through the water.

FIGURE 14 illustrates movement of the pontoon 95 in a wavy water surface. As the pontoon 95 moves forwardly in the water, as illustrated by an arrow 103 in FIGURE 14, waves of the water strikingly engage the forward end of the pontoon 95 and apply appreciable forces thereto, as illustrated by arrows 104, which tend to reduce the forward motion thereof. Thus, the pontoon 95 of FIGURES 12 and 14 does not represent the preferred embodiment of this invention but illustrates the action obtained by a pontoon which has a forward end portion which is not formed according to the preferred embodiment of this invention.

However, the pontoon 68, as shown in FIGURE 15, which is formed in accordance with the preferred embodiment of this invention, readily pierces the waves due to the fact that the point 70 thereof is below the longitudinal axis of the pontoon 68. Furthermore, due to the fact that the forward end of the pontoon '68 is shaped substantially as shown in FIGURES 13 and 15, the pontoon 68 engages waves with a minimum force.

Thus, the main pontoons 68 readily pierce the waves of water with a minimum force and tend to remain substantially horizontal during forward movement of the watercraft 30 as the watercraft 30 is propelled forwardly as illustrated by the arrow 90 in FIGURES 13 and 15.

If the watercraft 30 should travel upon a water surface which has primary waves which are spaced-apart a distance which is substantially equal to the length of the pontoons 68 or farther apart, the watercraft 30 sometimes moves at a downward angle as illustrated by an arrow 105 in FIGURE 10. Due to the fact that the main pontoons 68 are capable of piercing action, the forward portion of the pontoons 68 may enter a wave in the manner illustrated by an arrow 107 in FIGURE 10. When such action of the main pontoons 68 occurs and if the wave formation is of suflicient magnitude the auxiliary pontoons 40 6 also enter the water as shown in FIGURE 10. When the forward portion of the upper or auxiliary pontoons 40 enters the water, additional buoyancy is provided to the forward portion of the watercraft 30.

Thus, the forward portion of the watercraft 30 rises and the watercraft 30 tends to become horizontal, as illustrated in FIGURE 11. Thus, the watercraft 30 tends to remain horizontal, regardless of the surface conditions of the water upon which the watercraft 30 travels.

FIGURE 16 shows the forward end portion of a pontoon 106 which is a modification of the preferred embodiment of a part of this invention. The pontoon 106 has a nose 108 which extends forwardly from a position below the longitudinal axis thereof. It is preferable that the length of the nose 108 is in the range of two to four times the diameter of the pontoon 106. The height dimension of the nose 108 is preferably in the order of one-fourth the height dimension of the pontoon 106. The forward end of the nose 108 has a tip 110 which is preferably at the longitudinal axis of the nose 108.

Thus, during forward movement of the pontoon 106 as illustrated by an arrow 111 in FIGURE 16, an excellent piercing action occurs. Also, as the nose 108 enters the water, pressure forces upon the nose 108 are substantially equal on the top and bottom of the nose 108, as illustrated by arrows 112 in FIGURE 16.

Also, as shown in FIGURE 16, water pressure upon the forward end portion of the pontoon 106 is greater upon the upper forward portion thereof, as illustrated by arrows 116, than upon the lower forward end portion thereof, as illustrated by arrows 114. Therefore, the pontoon 106 tends to remain horizontal and stable during forward movement thereof. Thus, the pontoon 106 is capable of good wave piercing action and is also capable of stability as the pontoon 106 moves forwardly.

As the watercraft 30 travels upon the water, the resilient pivotal connections shown in FIGURE 5 permit relative movement between the legs 36 and 38 and the load carrier member 32, as illustrated in FIGURE 3. Furthermore, the resilient pivotal connection structure shown in FIG- URE 6 permits relative movement between each of the auxiliary pontoons 40 and its respective strut 60 and main pontoon 68, as illustrated in FIGURE 3. As the pontoons or floats 68 and 40 pierce the waves and enter and exit therefrom at various angles, some degree of shock or impact forces or the like are exerted thereupon. However, the entire structure of the watercraft 30 is capable of absorbing such forces as a result of the resilient pivotal connections illustrated in FIGURES 3, 5, and 6.

FIGURES 17 and 18 show a watercraft of this invention which is provided with a load carrier member 122. Leg members 126 and 128 are attached to the load carrier member 122. The attachment of the leg members 126 and 128 to the load carrier member 122 is preferably in the manner shown in FIGURE 5. However, other means of attachment may be satisfactory. The legs 126 and 128 are attached to auxiliary pontoons or floats 130 in the manner illustrated in FIGURE 6 or in any other suitable manner. A strut member 132 joins each auxiliary pontoon or float 130 to a main pontoon or float 134. Each pontoon 134 is shown as being provided with trim tabs or fins 136.

Each of the main pontoons or floats 134 is shown as having an elongate nose 138 which is similar to the nose 108 described above with respect to the pontoon 106 shown in FIGURE 16. However, each main pontoon or float 134 may have a forward end portion similar to that shown in FIGURES 13 and 15 or of any other suitable shape.

A strut 140 is attached to the load carrier member 122 and extends downwardly therefrom at the central portion thereof. A motor or engine housing 142 is attached to the strut 140 at the lower portion thereof. A propeller 144 or the like is operatively attached to an engine or motor, not shown, within the housing 142 for propulsion of the watercraft 120. Suitable conductors for control or for air or 7 the like may extend through the strut 140 from the load carrier member 122 to the motor or engine within the housing 142.

FIGURES 19, 20, and 21 illustrate movement of the pontoons 130 and 134 during travel thereof in a direction as shown by an arrow 145. The main pontoons 134 readily pierce the Water and substantially one-half of the volume thereof remains above the water, as shown in FIGURE 19.

The main pontoons 134 readily pierce waves, as illustrated in FIGURE 20, and if the waves are of suflicient height, the auxiliary pontoons 130 also pierce the waves and provide additional buoyancy to the watercraft 120 to urge the watercraft 120 toward a more level or more horizontal condition, as illustrated in FIGURE 21.

FIGURES 22 and 23 illustrate means which have been provided to reduce the frictional forces between the main pontoons 134 and the water at the surface of the pontoons 134. A conduit member 148 extends downwardly through each strut 132 to its respective main pontoon 134. Each conduit member 148 preferably has the upper end thereof adjacent the load carrier member 122. Within each pontoon 134 a closed chamber 150, which is shown in FIG- URES 22 and 23, is formed by partition members 152 and 154, shown in FIGURE 23. The remainder of the internal region of each pontoon 134 comprises an air chamber 155 which has openings 156 which communicate externally. Prefereably, at least some of the openings 156 are located in portions of the surface of the pontoon 134 at which the greatest changes in diameter thereof occur, as shown in FIGURE 23.

The conduit member 148 terminates within the air chamber 155. Air or other gas is forced downwardly through the conduit member 148 and into the air chamber 155.

As the watercraft 120 travels upon or through the water, air or other gas within the chamber 155 flows outwardly from the pontoon 134, as illustrated by arrows 158 in FIGURE 22, and mixes with the water at the surface of the pontoon 134. This mixture produces a foam or the like which covers substantially the entire exterior surface of the pontoon 134 which is within the water, as illustrated in FIGURE 23. The foam at the surface of the pontoon 134 serves as a lubricant and reduces the frictional forces between the pontoon 134 and the water as the pontoon 134 moves upon or through the water.

As the air or other gas flows from the pontoon 134 at portions of the surface thereof at which the greatest changes in diameter occur, the foam created provides a cushion and reduces the impact forces which normally occur at these regions of the pontoon 134. Thus, the pontoon 134 is capable of movement through water at a higher rate of speed and with the expenditure of less energy for such movement than would otherwise be possible.

It is to be understood that other means may be provided within the purview of this invention for applying a gas such as air or the like to the exterior surface of a pontoon for reducing frictional and impact forces thereupon.

'Each of the pontoons shown herein has forward and rear end portions which are substantially the same in shape. However, the pontoons do not need to have the same shape at each end thereof.

It is to be understood that a watercraft of this invention is capable of rapid travel over the surface of water which is wavy or smooth. Due to the fact that the pontoons are wave piercing float members, the direction of travel of the watercraft is continuously more horizontal than is possible with other watercraft which travel above the surface of the water. Thus, a load carried by the load carrier member travels more smoothly. Also, due to the fact that the pontoons are long and slender the energy required for movement through or upon the water is a minimum in consideration of the load carrying capacity thereof. Furthermore, the auxiliary pontoons of the watercraft provide means for stabilizing the travel of the watercraft when necessary and without adding resistance to forward motion except when employed for increasing the buoyancy of the watercraft.

Although the preferred embodiment of the invention has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation to provide structure within the scope of the appended claims and to accomplish the objects set forth.

The invention having thus been described, the following is claimed:

1. A watercraft comprising:

main float means, the main float means normally floating upon the surface of the water,

auxiliary float means being disposed at a higher elevation than the main float means,

load carrier means disposed at a higher elevation than the main float means,

means connecting the load carrier means to the float means.

2. The watercraft of claim 1 in which the main float means includes a pair of elongate main pontoons disposed in spaced-apart parallel relationship and laterally disposed with respect to the carrier means, the auxiliary float means including a pair of elongate auxiliary pontoons, there being one auxiliary pontoon disposed in substantially parallel relationship with each of the main pontoons.

3. The watercraft of claim 1 which includes propulsion means carried by the watercraft for movement thereof.

4. The watercraft of claim 3 in which the propulsion means are carried by the main float means.

5, The watercraft of claim 3 in which the propulsion means are carried by the load carrier means.

6. The watercraft of claim 1 in which the means connecting the load carrier means to the float means includes arm means, and means attaching the arm means to the load carrier means and to the float means.

7. The watercraft of claim 6 in which the means attaching the arm means to the load carrier means and to the float means includes pivotal means.

8. The watercraft of claim 7 in which the means attaching the arm means to the load carrier means and to the float means also includes resilient means.

9. The watercraft of claim 2 in which the means joining the pontoons to the load carrier means includes arm members which are pivotally attached to the load carrier means and which are attached to the auxiliary pontoons, and connector means joining each of the auxiliary pontoons to its respective main pontoon.

10. The watercraft of claim 2 in which each of the elongate pontoons is substantially circular in cross-section and in which the ratio between the length of each pontoon and the diameter thereof is in the range of from '10 to 1, to 50 to 1.

11. The watercraft of claim 1 which includes means for supplying air or other gas to the external surface of the float means so that a foam is created at the external surface of the float means.

12. The watercraft of claim 2 in which each of the main pontoons has a tip at the forward end thereof, the tip being below the longitudinal axis of the main pontoon.

13. The watercraft of claim 2 in which each main pontoon has an elongate nose at the forward end thereof.

14. The watercraft of claim 13 in which the elongate nose is below the longitudinal axis of the main pontoon.

15. The watercraft of claim 13 in which the elongate nose has a length which is substantially equal to two to four times the transverse dimension of the main pontoon.

16. The watercraft of claim 14 in which the elongate nose has a transverse dimension which is substantially equal to one-fourth the transverse dimension of the main pontoon.

17. The watercraft of claim 1 in which the load carrier means is disposed at a higher elevation than the auxiliary float means.

18. A watercraft comprising:

a plurality of main pontoons which are adapted to be normally in engagement with the surface of the 'Water for support of the watercraft,

a plurality of auxiliary pontoons, each auxiliary pontoon being disposed at a higher elevation than the main pontoons,

a load carrier member disposed at a higher elevation than the auxiliary pontoons,

connector means joining the load carrier member to the auxiliary pontoons and to the main pontoons.

19. The watercraft of claim 18 in which the main pontoons are elongate.

20. The watercraft of claim 19 in which the auxiliary pontoons are elongate and substantially parallel with the main pontoons.

21. The watercraft of claim 18 in which the connector means includes a plurality of leg members, there being at least one leg member connecting the load carrier member to each of the auxiliary pontoons, and a plurailty of strut members, there being at least one strut member connecting each auxiliary pontoon to a main pontoon.

22. The watercraft of claim 18 in which each main pontoon has a volume such that substantially one-half of the main pontoon is normally submerged when a normal load is carried by the load carrier member.

23. The watercraft of claim 18 in which each main pontoon has a plurality of fluid outlets at the exterior surface thereof, means for supplying a gas to the main pontoons and for forcing the gas outwardly from the main pontoons through the fluid outlets.

24. The watercraft of claim 20 in which each main pontoon is substantially circular in cross-section and in which the ratio between the length of each main pontoon and the diameter thereof is in the range of from 10 to 1, to 50 to 1.

References Cited UNITED STATES PATENTS 795,002 7/1905 Nelson 114-61 1,757,174 5/1930 Douglas 114-61 2,347,959 5/1944 Moore et al. 1146-1 3,205,847 9/1965 Smith 114-67 FOREIGN PATENTS 41,617 10/ 1965 Germany.

ANDREW H. FARRELL, Primary Examiner.

US. Cl. X.R. 114--67 

